This invention relates to a tool for resetting the gap of an aircraft-type spark plug.
Aircraft-type spark plugs normally include a central cylindrical electrode and a pair of strip-like outer electrodes located on opposite sides of the central electrode and bent so that their ends extend parallel to the central cylindrical electrode. During their operation, the electrodes wear away, and after a period such as 75 hours of flight time the gaps between the central and outer electrodes must be reset. Heretofore, the available resetting tools utilized a frame designed to be mounted on a bench, and a threaded member which could be turned to advance against an outer electrode while the mechanic held a gauge between the outer and center electrodes to accurately reset the gap. Such a tool had been too cumbersome for pilots of small planes to carry in their tool kit so the pilots could reset the gap when operating in countries where reliable maintenance services are not available. In addition, the resetting devices required several steps in their operation which retarded the work of mechanics who wished to reset a set of spark plugs quickly.